<nav class="box">
    <a href="index.html" class="box box-col box-center">
        <span class="nav-icon icon-home"></span>
        <span class="font12">首页</span>
    </a>
    <a href="send.html" class="box box-center">
        <span class="nav-middle-icon"></span>
    </a>
    <a href="mine.html"  class="box box-col box-center">
        <span class="nav-icon icon-mine"></span>
        <span class="font12">我的</span>
    </a>
</nav>